##############################################################################
#
# Copyright (c) 2003 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Classes to support implementing `IContained`
"""
# pylint:disable=too-many-lines
import zope.component
from zope.event import notify
from zope.interface import Interface
from zope.interface import implementedBy
from zope.interface import providedBy
from zope.interface.declarations import Provides
from zope.interface.declarations import getObjectSpecification
from zope.lifecycleevent import ObjectAddedEvent
from zope.lifecycleevent import ObjectModifiedEvent
from zope.lifecycleevent import ObjectMovedEvent
from zope.lifecycleevent import ObjectRemovedEvent
from zope.location.interfaces import IContained
from zope.location.interfaces import ILocation
from zope.location.interfaces import ISublocations
from zope.security.checker import CombinedChecker
from zope.security.checker import selectChecker
from zope.container._proxy import ContainedProxyBase
from zope.container._proxy import getProxiedObject
from zope.container.i18n import ZopeMessageFactory as _
from zope.container.interfaces import IContainerModifiedEvent
from zope.container.interfaces import INameChooser
from zope.container.interfaces import IReservedNames
from zope.container.interfaces import NameReserved
try:
from ZODB.interfaces import IBroken
except ImportError: # pragma: no cover
class IBroken(Interface): # pylint:disable=inherit-non-class
pass
[docs]
@zope.interface.implementer(IContained)
class Contained:
"""
Simple mix-in that defines ``__parent__`` and ``__name__``
attributes and implements `IContained`.
"""
__parent__ = __name__ = None
[docs]
@zope.interface.implementer(IContainerModifiedEvent)
class ContainerModifiedEvent(ObjectModifiedEvent):
"""The container has been modified."""
[docs]
def dispatchToSublocations(object, event): # pylint:disable=redefined-builtin
"""Dispatch an event to sublocations of a given object
When a move event happens for an object, it's important to notify
subobjects as well.
We do this based on locations.
Suppose, for example, that we define some location objects.
>>> @zope.interface.implementer(ILocation)
... class L(object):
... def __init__(self, name):
... self.__name__ = name
... self.__parent__ = None
... def __repr__(self):
... return '%s(%s)' % (
... self.__class__.__name__, str(self.__name__))
>>> @zope.interface.implementer(ISublocations)
... class C(L):
... def __init__(self, name, *subs):
... L.__init__(self, name)
... self.subs = subs
... for sub in subs:
... sub.__parent__ = self
... def sublocations(self):
... return self.subs
>>> c = C(1,
... C(11,
... L(111),
... L(112),
... ),
... C(12,
... L(121),
... L(122),
... L(123),
... L(124),
... ),
... L(13),
... )
Now, if we call the dispatcher, it should call event handlers
for all of the objects.
Lets create an event handler that records the objects it sees:
>>> seen = []
>>> def handler(ob, event):
... seen.append((ob, event.object))
Note that we record the the object the handler is called on as
well as the event object:
Now we'll register it:
>>> from zope import component
>>> from zope.lifecycleevent.interfaces import IObjectMovedEvent
>>> component.provideHandler(handler, [None, IObjectMovedEvent])
We also register our dispatcher:
>>> component.provideHandler(dispatchToSublocations,
... [None, IObjectMovedEvent])
We can then call the dispatcher for the root object:
>>> event = ObjectRemovedEvent(c)
>>> dispatchToSublocations(c, event)
Now, we should have seen all of the subobjects:
>>> seenreprs = sorted(map(repr, seen))
>>> seenreprs
['(C(11), C(1))', '(C(12), C(1))', '(L(111), C(1))',""" \
""" '(L(112), C(1))', '(L(121), C(1))', '(L(122), C(1))',""" \
""" '(L(123), C(1))', '(L(124), C(1))', '(L(13), C(1))']
We see that we get entries for each of the subobjects and
that,for each entry, the event object is top object.
This suggests that location event handlers need to be aware that
the objects they are called on and the event objects could be
different.
"""
subs = ISublocations(object, None)
if subs is not None:
for sub in subs.sublocations():
zope.component.handle(sub, event)
[docs]
class ContainerSublocations:
"""Get the sublocations for a container
Obviously, this is the container values:
>>> class MyContainer(object):
... def __init__(self, **data):
... self.data = data
... def __iter__(self):
... return iter(self.data)
... def __getitem__(self, key):
... return self.data[key]
>>> container = MyContainer(x=1, y=2, z=42)
>>> adapter = ContainerSublocations(container)
>>> sublocations = list(adapter.sublocations())
>>> sublocations.sort()
>>> sublocations
[1, 2, 42]
"""
def __init__(self, container):
self.container = container
def sublocations(self):
container = self.container
for key in container:
yield container[key]
[docs]
def containedEvent(object, container, name=None):
"""Establish the containment of the object in the container
The object and necessary event are returned. The object may be a
`ContainedProxy` around the original object. The event is an added
event, a moved event, or None.
If the object implements `IContained`, simply set its ``__parent__``
and ``__name__`` attributes:
>>> container = {}
>>> item = Contained()
>>> x, event = containedEvent(item, container, 'foo')
>>> x is item
True
>>> item.__parent__ is container
True
>>> item.__name__
'foo'
We have an added event:
>>> event.__class__.__name__
'ObjectAddedEvent'
>>> event.object is item
True
>>> event.newParent is container
True
>>> event.newName
'foo'
>>> event.oldParent
>>> event.oldName
Now if we call contained again:
>>> x2, event = containedEvent(item, container, 'foo')
>>> x2 is item
True
>>> item.__parent__ is container
True
>>> item.__name__
'foo'
We don't get a new added event:
>>> event
If the object already had a parent but the parent or name was
different, we get a moved event:
>>> x, event = containedEvent(item, container, 'foo2')
>>> event.__class__.__name__
'ObjectMovedEvent'
>>> event.object is item
True
>>> event.newParent is container
True
>>> event.newName
'foo2'
>>> event.oldParent is container
True
>>> event.oldName
'foo'
If the *object* implements `ILocation`, but not `IContained`, set its
``__parent__`` and ``__name__`` attributes *and* declare that it
implements `IContained`:
>>> from zope.location import Location
>>> from zope.location.interfaces import IContained
>>> item = Location()
>>> IContained.providedBy(item)
False
>>> x, event = containedEvent(item, container, 'foo')
>>> x is item
True
>>> item.__parent__ is container
True
>>> item.__name__
'foo'
>>> IContained.providedBy(item)
True
If the *object* doesn't even implement `ILocation`, put a
`ContainedProxy` around it:
>>> item = []
>>> x, event = containedEvent(item, container, 'foo')
>>> x is item
False
>>> x.__parent__ is container
True
>>> x.__name__
'foo'
Make sure we don't lose existing directly provided interfaces.
>>> from zope.interface import Interface, directlyProvides
>>> class IOther(Interface):
... pass
>>> from zope.location import Location
>>> item = Location()
>>> directlyProvides(item, IOther)
>>> IOther.providedBy(item)
True
>>> x, event = containedEvent(item, container, 'foo')
>>> IOther.providedBy(item)
True
"""
if not IContained.providedBy(object):
if ILocation.providedBy(object):
zope.interface.alsoProvides(object, IContained)
else:
object = ContainedProxy(object)
oldparent = object.__parent__
oldname = object.__name__
if oldparent is container and oldname == name:
# No events
return object, None
object.__parent__ = container
object.__name__ = name
if oldparent is None or oldname is None:
event = ObjectAddedEvent(object, container, name)
else:
event = ObjectMovedEvent(object, oldparent, oldname, container, name)
return object, event
[docs]
def contained(object, container, name=None):
"""Establish the containment of the object in the container
Just return the contained object without an event. This is a convenience
"macro" for:
``containedEvent(object, container, name)[0]``
This function is only used for tests.
"""
return containedEvent(object, container, name)[0]
[docs]
def notifyContainerModified(object, *descriptions):
"""Notify that the container was modified."""
notify(ContainerModifiedEvent(object, *descriptions))
_SENTINEL = object()
def checkAndConvertName(name):
# Basic name checks, including converting bytes to text.
# Not a documented public API function.
if isinstance(name, bytes):
try:
name = name.decode('ascii')
except UnicodeError:
raise TypeError("name not unicode or ascii string")
elif not isinstance(name, str):
raise TypeError("name not unicode or ascii string")
if not name:
raise ValueError("empty names are not allowed")
return name
[docs]
def setitem(container, setitemf, name, object):
r"""Helper function to set an item and generate needed events
This helper is needed, in part, because the events need to get
published after the *object* has been added to the *container*.
If the item implements `IContained`, simply set its ``__parent__``
and ``__name__`` attributes:
>>> class IItem(zope.interface.Interface):
... pass
>>> @zope.interface.implementer(IItem)
... class Item(Contained):
... def setAdded(self, event):
... self.added = event
... def setMoved(self, event):
... self.moved = event
>>> from zope.lifecycleevent.interfaces import IObjectAddedEvent
>>> from zope.lifecycleevent.interfaces import IObjectMovedEvent
>>> from zope import component
>>> component.provideHandler(lambda obj, event: obj.setAdded(event),
... [IItem, IObjectAddedEvent])
>>> component.provideHandler(lambda obj, event: obj.setMoved(event),
... [IItem, IObjectMovedEvent])
>>> item = Item()
>>> container = {}
>>> setitem(container, container.__setitem__, 'c', item)
>>> container['c'] is item
True
>>> item.__parent__ is container
True
>>> item.__name__
'c'
If we run this using the testing framework, we'll use `getEvents` to
track the events generated:
>>> from zope.component.eventtesting import getEvents
>>> from zope.lifecycleevent.interfaces import IObjectModifiedEvent
We have an added event:
>>> len(getEvents(IObjectAddedEvent))
1
>>> event = getEvents(IObjectAddedEvent)[-1]
>>> event.object is item
True
>>> event.newParent is container
True
>>> event.newName
'c'
>>> event.oldParent
>>> event.oldName
As well as a modification event for the container:
>>> len(getEvents(IObjectModifiedEvent))
1
>>> getEvents(IObjectModifiedEvent)[-1].object is container
1
The item's hooks have been called:
>>> item.added is event
1
>>> item.moved is event
1
We can suppress events and hooks by setting the ``__parent__`` and
``__name__`` first:
>>> item = Item()
>>> item.__parent__, item.__name__ = container, 'c2'
>>> setitem(container, container.__setitem__, 'c2', item)
>>> len(container)
2
>>> len(getEvents(IObjectAddedEvent))
1
>>> len(getEvents(IObjectModifiedEvent))
1
>>> getattr(item, 'added', None)
>>> getattr(item, 'moved', None)
If the item had a parent or name (as in a move or rename),
we generate a move event, rather than an add event:
>>> setitem(container, container.__setitem__, 'c3', item)
>>> len(container)
3
>>> len(getEvents(IObjectAddedEvent))
1
>>> len(getEvents(IObjectModifiedEvent))
2
>>> len(getEvents(IObjectMovedEvent))
2
(Note that we have 2 move events because add are move events.)
We also get the move hook called, but not the add hook:
>>> event = getEvents(IObjectMovedEvent)[-1]
>>> getattr(item, 'added', None)
>>> item.moved is event
1
If we try to replace an item without deleting it first, we'll get
an error:
>>> setitem(container, container.__setitem__, 'c', [])
Traceback (most recent call last):
...
KeyError: 'c'
>>> del container['c']
>>> setitem(container, container.__setitem__, 'c', [])
>>> len(getEvents(IObjectAddedEvent))
2
>>> len(getEvents(IObjectModifiedEvent))
3
If the object implements `ILocation`, but not `IContained`, set it's
``__parent__`` and ``__name__`` attributes *and* declare that it
implements `IContained`:
>>> from zope.location import Location
>>> item = Location()
>>> IContained.providedBy(item)
0
>>> setitem(container, container.__setitem__, 'l', item)
>>> container['l'] is item
1
>>> item.__parent__ is container
1
>>> item.__name__
'l'
>>> IContained.providedBy(item)
1
We get new added and modification events:
>>> len(getEvents(IObjectAddedEvent))
3
>>> len(getEvents(IObjectModifiedEvent))
4
If the object doesn't even implement `ILocation`, put a
`ContainedProxy` around it:
>>> item = []
>>> setitem(container, container.__setitem__, 'i', item)
>>> container['i']
[]
>>> container['i'] is item
0
>>> item = container['i']
>>> item.__parent__ is container
1
>>> item.__name__
'i'
>>> IContained.providedBy(item)
1
>>> len(getEvents(IObjectAddedEvent))
4
>>> len(getEvents(IObjectModifiedEvent))
5
We'll get type errors if we give keys that aren't unicode or ascii keys:
>>> setitem(container, container.__setitem__, 42, item)
Traceback (most recent call last):
...
TypeError: name not unicode or ascii string
>>> setitem(container, container.__setitem__, None, item)
Traceback (most recent call last):
...
TypeError: name not unicode or ascii string
>>> setitem(container, container.__setitem__, b'hello \xc8', item)
Traceback (most recent call last):
...
TypeError: name not unicode or ascii string
and we'll get a value error of we give an empty string or unicode:
>>> setitem(container, container.__setitem__, '', item)
Traceback (most recent call last):
...
ValueError: empty names are not allowed
>>> setitem(container, container.__setitem__, '', item)
Traceback (most recent call last):
...
ValueError: empty names are not allowed
"""
# Do basic name check:
name = checkAndConvertName(name)
old = container.get(name, _SENTINEL)
if old is object:
return
if old is not _SENTINEL:
raise KeyError(name)
object, event = containedEvent(object, container, name)
setitemf(name, object)
if event:
notify(event)
notifyContainerModified(container)
fixing_up = False
[docs]
def uncontained(object, container, name=None):
"""Clear the containment relationship between the *object* and
the *container*.
If we run this using the testing framework, we'll use `getEvents` to
track the events generated:
>>> from zope.component.eventtesting import getEvents
>>> from zope.lifecycleevent.interfaces import IObjectModifiedEvent
>>> from zope.lifecycleevent.interfaces import IObjectRemovedEvent
We'll start by creating a container with an item:
>>> class Item(Contained):
... pass
>>> item = Item()
>>> container = {'foo': item}
>>> x, event = containedEvent(item, container, 'foo')
>>> item.__parent__ is container
1
>>> item.__name__
'foo'
Now we'll remove the item. It's parent and name are cleared:
>>> uncontained(item, container, 'foo')
>>> item.__parent__
>>> item.__name__
We now have a new removed event:
>>> len(getEvents(IObjectRemovedEvent))
1
>>> event = getEvents(IObjectRemovedEvent)[-1]
>>> event.object is item
1
>>> event.oldParent is container
1
>>> event.oldName
'foo'
>>> event.newParent
>>> event.newName
As well as a modification event for the container:
>>> len(getEvents(IObjectModifiedEvent))
1
>>> getEvents(IObjectModifiedEvent)[-1].object is container
1
Now if we call uncontained again:
>>> uncontained(item, container, 'foo')
We won't get any new events, because __parent__ and __name__ are None:
>>> len(getEvents(IObjectRemovedEvent))
1
>>> len(getEvents(IObjectModifiedEvent))
1
But, if either the name or parent are not ``None`` and they are not the
container and the old name, we'll get a modified event but not a removed
event.
>>> item.__parent__, item.__name__ = container, None
>>> uncontained(item, container, 'foo')
>>> len(getEvents(IObjectRemovedEvent))
1
>>> len(getEvents(IObjectModifiedEvent))
2
>>> item.__parent__, item.__name__ = None, 'bar'
>>> uncontained(item, container, 'foo')
>>> len(getEvents(IObjectRemovedEvent))
1
>>> len(getEvents(IObjectModifiedEvent))
3
If one tries to delete a Broken object, we allow them to do
just that.
>>> class Broken(object):
... __Broken_state__ = {}
>>> broken = Broken()
>>> broken.__Broken_state__['__name__'] = 'bar'
>>> broken.__Broken_state__['__parent__'] = container
>>> container['bar'] = broken
>>> uncontained(broken, container, 'bar')
>>> len(getEvents(IObjectRemovedEvent))
2
"""
try:
oldparent = object.__parent__
oldname = object.__name__
except AttributeError:
# The old object doesn't implements IContained
# Maybe we're converting old data:
if hasattr(object, '__Broken_state__'):
state = object.__Broken_state__
oldparent = state['__parent__']
oldname = state['__name__']
else:
if not fixing_up:
raise
oldparent = None
oldname = None
if oldparent is not container or oldname != name:
if oldparent is not None or oldname is not None:
notifyContainerModified(container)
return
event = ObjectRemovedEvent(object, oldparent, oldname)
notify(event)
if not IBroken.providedBy(object):
object.__parent__ = None
object.__name__ = None
notifyContainerModified(container)
@zope.interface.implementer(INameChooser)
class NameChooser:
def __init__(self, context):
self.context = context
def checkName(self, name, object): # pylint:disable=redefined-builtin
"""See zope.container.interfaces.INameChooser
We create and populate a dummy container
>>> from zope.container.sample import SampleContainer
>>> container = SampleContainer()
>>> container['foo'] = 'bar'
>>> from zope.container.contained import NameChooser
An invalid name raises a ValueError:
>>> NameChooser(container).checkName('+foo', object())
Traceback (most recent call last):
...
ValueError: Names cannot begin with '+' or '@' or contain '/'
A name that already exists raises a KeyError:
>>> NameChooser(container).checkName('foo', object())
Traceback (most recent call last):
...
KeyError: 'The given name is already being used'
A name must be a string or unicode string:
>>> NameChooser(container).checkName(2, object())
Traceback (most recent call last):
...
TypeError: ('Invalid name type', <class 'int'>)
A correct name returns True:
>>> NameChooser(container).checkName('2', object())
True
We can reserve some names by providing a IReservedNames adapter
to a container:
>>> from zope.container.interfaces import IContainer
>>> @zope.component.adapter(IContainer)
... @zope.interface.implementer(IReservedNames)
... class ReservedNames(object):
...
... def __init__(self, context):
... self.reservedNames = set(('reserved', 'other'))
>>> zope.component.getSiteManager().registerAdapter(ReservedNames)
>>> NameChooser(container).checkName('reserved', None)
Traceback (most recent call last):
...
zope.container.interfaces.NameReserved: reserved
"""
if isinstance(name, bytes):
name = name.decode('ascii')
elif not isinstance(name, str):
raise TypeError("Invalid name type", type(name))
if not name:
raise ValueError(
_("An empty name was provided. Names cannot be empty.")
)
if name[:1] in '+@' or '/' in name:
raise ValueError(
_("Names cannot begin with '+' or '@' or contain '/'")
)
reserved = IReservedNames(self.context, None)
if reserved is not None:
if name in reserved.reservedNames:
raise NameReserved(name)
if name in self.context:
raise KeyError(
_("The given name is already being used")
)
return True
def chooseName(self, name, object): # pylint:disable=redefined-builtin
"""See zope.container.interfaces.INameChooser
The name chooser is expected to choose a name without error
We create and populate a dummy container
>>> from zope.container.sample import SampleContainer
>>> container = SampleContainer()
>>> container['foobar.old'] = 'rst doc'
>>> from zope.container.contained import NameChooser
the suggested name is converted to unicode:
>>> NameChooser(container).chooseName('foobar', object())
'foobar'
>>> NameChooser(container).chooseName(b'foobar', object())
'foobar'
If it already exists, a number is appended but keeps the same
extension:
>>> NameChooser(container).chooseName('foobar.old', object())
'foobar-2.old'
Bad characters are turned into dashes:
>>> NameChooser(container).chooseName('foo/foo', object())
'foo-foo'
If no name is suggested, it is based on the object type:
>>> NameChooser(container).chooseName('', [])
'list'
"""
container = self.context
# convert to unicode and remove characters that checkName does not
# allow
if isinstance(name, bytes):
name = name.decode('ascii')
if not isinstance(name, str):
try:
name = str(name)
except Exception:
name = ''
name = name.replace('/', '-').lstrip('+@')
if not name:
name = object.__class__.__name__
if isinstance(name, bytes):
name = name.decode('ascii')
# for an existing name, append a number.
# We should keep client's os.path.extsep (not ours), we assume it's '.'
dot = name.rfind('.')
if dot >= 0:
suffix = name[dot:]
name = name[:dot]
else:
suffix = ''
n = name + suffix
i = 1
while n in container:
i += 1
n = name + '-' + str(i) + suffix
# Make sure the name is valid. We may have started with something bad.
self.checkName(n, object)
return n
[docs]
class DecoratorSpecificationDescriptor(
zope.interface.declarations.ObjectSpecificationDescriptor):
"""Support for interface declarations on decorators
>>> from zope.interface import Interface, directlyProvides, implementer
>>> class I1(Interface):
... pass
>>> class I2(Interface):
... pass
>>> class I3(Interface):
... pass
>>> class I4(Interface):
... pass
>>> @implementer(I1)
... class D1(ContainedProxy):
... pass
>>> @implementer(I2)
... class D2(ContainedProxy):
... pass
>>> @implementer(I3)
... class X:
... pass
>>> x = X()
>>> directlyProvides(x, I4)
Interfaces of X are ordered with the directly-provided interfaces first
>>> [interface.getName() for interface in list(providedBy(x))]
['I4', 'I3']
When we decorate objects, what order should the interfaces come in? One
could argue that decorators are less specific, so they should come last.
This is subject to respecting the C3 resolution order, of course.
>>> [interface.getName() for interface in list(providedBy(D1(x)))]
['I4', 'I3', 'I1', 'IContained', 'IPersistent']
>>> [interface.getName() for interface in list(providedBy(D2(D1(x))))]
['I4', 'I3', 'I1', 'I2', 'IContained', 'IPersistent']
"""
def __get__(self, inst, cls=None):
if inst is None: # pragma: no cover (Not sure how we can get here)
return getObjectSpecification(cls)
provided = providedBy(getProxiedObject(inst))
# Use type rather than __class__ because inst is a proxy and
# will return the proxied object's class.
cls = type(inst)
implemented_by_cls = implementedBy(cls)
for iface in list(provided):
if implemented_by_cls.isOrExtends(iface):
provided = provided - iface
return Provides(cls, provided)
[docs]
class DecoratedSecurityCheckerDescriptor:
"""
Descriptor for a Decorator that provides a decorated security
checker.
>>> class WithChecker(object):
... __Security_checker__ = object()
>>> class D1(ContainedProxy):
... pass
>>> d = D1(object())
>>> d.__Security_checker__ # doctest: +ELLIPSIS
<...Checker...>
An existing checker is added to this one:
>>> d = D1(WithChecker())
>>> d.__Security_checker__ # doctest: +ELLIPSIS
<...CombinedChecker...>
"""
def __get__(self, inst, cls=None):
if inst is None: # pragma: no cover (Not sure how we can get here)
return self
proxied_object = getProxiedObject(inst)
checker = getattr(proxied_object, '__Security_checker__', None)
if checker is None:
checker = selectChecker(proxied_object)
wrapper_checker = selectChecker(inst)
if wrapper_checker is None: # pragma: no cover
return checker
if checker is None:
return wrapper_checker
return CombinedChecker(wrapper_checker, checker)
[docs]
class ContainedProxyClassProvides(zope.interface.declarations.ClassProvides):
"""
Delegates __provides__ to the instance.
>>> class D1(ContainedProxy):
... pass
>>> class Base(object):
... pass
>>> base = Base()
>>> d = D1(base)
>>> d.__provides__ = 42
>>> base.__provides__
42
>>> del d.__provides__
>>> hasattr(base, '__provides__')
False
"""
def __set__(self, inst, value):
inst = getProxiedObject(inst)
inst.__provides__ = value
def __delete__(self, inst):
# CPython can hit this, PyPy/PURE_PYTHON cannot
inst = getProxiedObject(inst)
del inst.__provides__
[docs]
@zope.interface.implementer(IContained)
class ContainedProxy(ContainedProxyBase):
"""
Wraps an object to implement :class:`zope.container.interfaces.IContained`
with a new ``__name__`` and ``__parent__``.
The new object provides everything the wrapped object did, plus
`IContained` and `IPersistent`.
"""
# Prevent proxies from having their own instance dictionaries:
__slots__ = ()
__safe_for_unpickling__ = True
__providedBy__ = zope.proxy.non_overridable(
DecoratorSpecificationDescriptor())
__Security_checker__ = zope.proxy.non_overridable(
DecoratedSecurityCheckerDescriptor())
ContainedProxy.__provides__ = ContainedProxyClassProvides(ContainedProxy, type)